(1) Field of the Invention
The present invention relates to stress relief backshells for cable connectors and more particularly to a backshell assembly in both angled and straight configurations which can be easily removed and replaced without disassembling the connector.
(2) Description of the Prior Art
Stress relief backshell assemblies are well known in the art. The purpose of these assemblies is to prevent separation of cable element wires from connector assemblies caused by cable tension or bending. The weakest point in a multi-element electrical cable is where the cable elements are connected to a termination device or to another cable. Any tension in the cable may cause uncoupling of cable elements from the connector, and a corresponding loss of data or power transfer. Likewise, bending of a cable near one of its attached connectors causes tension in the outer elements of the cable resulting in possible element separation from the connector and loss of electrical contact.
Backshell assemblies were devised to allow stress due to tension or bending to be transmitted away from the joint between the cable and connector by the connector and backshell instead of by the cable elements. Present backshells commonly have a ring-shaped front portion which engages the connector, two ear portions extending from the front portion rearward along the cable away from the connector, two clamp members, positioned at the end of the ear portions away from the connector, for compressing the cable therebetween at the distal end of the ear portions, and fasteners to tighten the clamp members against the cable. When the cable/connector assembly is placed in tension, friction between the backshell clamp and the cable transmits stress from the cable/clamp joint directly to the connector assembly. This stress transmission through the backshell acts to maintain slack in the cable at the connection between the elements and the connector thereby preventing detachment. When a cable is bent at or near the connection, the backshell absorbs the bending stress by providing a rigid structure from the clamp to the connector.
Present stress relief backshells are available in many configurations and sizes. Variations on the basic design include a widened front ring portion extending along the cable to provide protection from compression and friction and an angled front ring portion or angled ears to accommodate a bend in the cable near the connection. Backshells are available for many kinds of connectors, including multi-element, coaxial, and telephone cables.
The disadvantage of prior art circular backshells is that if the configuration of the cable changes and an angled backshell is needed, the connector must be disassembled and removed from the end of the cable. The prior art backshell must be inserted over the end of the cable and the connector then must be reassembled to the cable elements. Reassembly of the connector involves insertion and electrical connection of a plurality of wires or cable elements into apertures on the rear side of the connector. Disassembling and assembling a cable connector joint can take up to six hours. Eliminating the need to remove connectors when changing the configuration of a cable saves a great deal of time and labor particularly in a research and development environment.